Injection molding machines have been known in the art for some time. Typical injection molding machines are disclosed in U.S. Pat. No. 3,465,387 to Allard et al. and in U.S. Pat. No. 5,382,158 to Herbst, the specifications and drawings of which are herein expressly incorporated by reference. A standard molding press has a base, a fixed mold plate secured to the base, a fixed mold half carried on the fixed mold plate, and a movable mold plate displaceable on the base longitudinally forward away from the fixed mold half and backward toward the fixed mold half. A movable mold half is carried on the movable plate and fittable with the fixed mold half. Typically, a plurality of piston cylinders are mounted on the fixed plate with their piston rods projecting through the fixed plate and secured to the movable mold plate. Pressurization of these piston cylinders holds the mold tightly closed as molding material is injected into the closed mold and the material cures.
To increase the capacity of these conventional injection molding machines, stack mold assemblies have been developed. A typical stack mold assembly is disclosed in U.S. Pat. No. 4,604,258 to Valyi, the specifications and drawings of which are herein expressly incorporated by reference. A conventional stack mold uses at least two injection molds back-to-back, each having a mold cavity. The location of the cavities on opposing faces of the stack molds enables the same clamping and injection forces to be applied to the plurality of cavities at the same time, thereby increasing the output of the injection molding machine.
As the needs of industry grow, molded parts fashioned in the above manner have increased in size, thereby requiring larger and heavier stack molds. As these stack molds increase in size and weight, it becomes increasingly difficult to support them within the injection molding machine. Therefore, it is an object of the present invention to provide a stack mold support that enables lateral movement of the stack mold during clamping while simultaneously supporting the stack mold within the injection molding machine.